<template>
  <div class="app-container">
    <el-input v-model="filterText" placeholder="Filter keyword" style="margin-bottom: 30px" />

    <el-tree
      ref="tree2"
      :data="data2"
      :props="defaultProps"
      :filter-node-method="filterNode"
      class="filter-tree"
      default-expand-all
    />
  </div>
</template>

<script>
export default {
  data() {
    return {
      filterText: "",
      data2: [
        {
          id: 1,
          label: "Level one 1",
          children: [
            {
              id: 4,
              label: "Level two 1-1",
              children: [
                {
                  id: 9,
                  label: "Level three 1-1-1",
                },
                {
                  id: 10,
                  label: "Level three 1-1-2",
                },
              ],
            },
          ],
        },
        {
          id: 2,
          label: "Level one 2",
          children: [
            {
              id: 5,
              label: "Level two 2-1",
            },
            {
              id: 6,
              label: "Level two 2-2",
            },
          ],
        },
        {
          id: 3,
          label: "Level one 3",
          children: [
            {
              id: 7,
              label: "Level two 3-1",
            },
            {
              id: 8,
              label: "Level two 3-2",
            },
          ],
        },
      ],
      defaultProps: {
        children: "children",
        label: "label",
      },
    };
  },
  watch: {
    filterText(val) {
      this.$refs.tree2.filter(val);
    },
  },

  methods: {
    filterNode(value, data) {
      if (!value) return true;
      return data.label.indexOf(value) !== -1;
    },
  },
};
</script>
